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Thursday, September 2, 2010

Everything you need to know about heart failure

To understand Congestive Heart Failure (CHF) you must first understand that the heart basically has two functions:

1) to pump oxygenated blood from the lungs through the body, and

2) to pump unoxygenated blood from the tissues to the lungs where it can pick up oxygen that you breath in.

Actually, you have two hearts. The right side of your heart pumps blood to the lungs, and the left side pumps blood to the body. The right heart is generally a smaller pump because blood pressure in the lungs is relatively low (about 15) compared to the blood pressure in the body (normal about 120/80).

Congestive Heart failure usually refers to a is a condition where the left heart becomes unable to pump blood through the body in order to fully oxygenate tissues and organs that work to keep the body functioning as a system. Without adequate blood flow, tissues and organs will fail to perform their jobs, and the body will die.

When a heart is in failure it is unable to maintain an adequate cardiac output (CO) which is the volume of blood pumped from the heart per minute. CO is the product of both the stroke volume and heart rate. Heart rate (HR) is simply the number of beats per minute. Strove Volume (SV) is the volume of blood pumped from the heart per beat. Thus, CO = HR times stroke volume.

Thus, by using this simple formula, you can see that anything that decreases the heart rate, or the strength of the heart will decrease the amount of blood coming from the heart to keep the body functioning.

Without doing extensive testing, an easy way to measure cardiac output is by taking a blood pressure. And even easier way is by simply taking a pulse.

As CHF progresses, and as the heart becomes too weak to effectively pump blood through the body, blood will back up into the vessels in the lungs, thus increasing the pulmonary vascular resistance, or blood pressure in the lungs. As this happens, blood will seep out of the blood vessels and into the lungs, causing increased fluid build up in the lungs called pulmonary edema.

Due to the high blood pressure in the lungs, this will actually push the fluid up and around the air passages in the lungs (bronchioles) and thus cause a wheeze, which is technically called a cardiac wheeze or cardiac asthma. This wheeze cannot be treated with a breathing treatment, although it quite often is.

Causes of CHF?

1. Hypertension: The extra work needed to pump blood through years of narrowed blood vessels will eventually tire out the heart, thus causing it to become a less effective pump. In fact, 60% of heart failure cases are the result of high systemic blood pressure and coronary artery disease.

2. Coronary Artery Disease (CAD): According to the National Heart, Lung and Blood Institute (NHLBI), CAD is a disease whereby plaque builds up inside the coronary arteries (arteries that supply oxygenated blood to the heart) . This plaque build up is called atherosclerosis, and will slowly cause these arteries to narrow, and thus force the heart to work harder to oxygenate itself. This can often lead to portions of plaque to break free, forming a clot in the heart, and causing a Mycardial Infarction, otherwise known as a heart attack.

3. Mycardial Infarction: This is where plaque from diseased coronary arteries breaks free and blocks blood flow to a part of the heart, causing heart (muscle) tissue in that area to die.

4. Pulmonary Hypertension: This is where the blood pressure in the lungs is high because of pulmonary disease, such as COPD, Cystic Fibrosis (CF), Pulmonary Fibrosis (PF), etc. As the
lungs become stiffer (PF) or the air passages in your lungs become narrowed (bronchospasm), or blocked by thick mucus or mucus (CF) the patient is unable to cough up (COPD), this ultimately causes the blood pressure in the lungs to increase. This causes the right heart to work extra hard to pump blood through the lungs, and ultimately causes the right heart to become a bigger muscle (cor pulmonale). As with any muscle, when you use it more than normal it becomes larger. Ultimately, after years of being overworked, this weakens the heart.

Thus, CHF is usually a sign of end stage lung disease.

5. Cor Pulmonale: This is when the right heart fails due to pulmonary disease. This is responsible for 10-30% of admissions for CHF.

6. Heart Disease: About 30-40% of heart failure is caused by heart disease

7. Heart Valve Disease: This constitutes about 20% of heart failure. When the valves of the heart fail to work properly, this causes the heart to become a weaker pump.

8. Congenital Heart Defects: These are diseases a person is born with, and you can read about here.

9. Drug abuse: Amphetemines, heroin, cocaine and other medicines may actually numb the heart so much that it becomes a less effective pump.

10. Alcohol Abuse: Years of abusing your body.

11. Infection: Influenza, mumps, and rabies are infections that can stun the heart, as are various bacterial infections (streptococcal, rheumatic heart disease). Likewise, sepsis (a systemic blood infection) can also weaken the heart's ability to pump blood.

12. Other diseases: Leukemia, neurologic disorders (Duchenne's muscular dystrophy, Multi-system organ failure, Sepsis, Trauma, cardiac tamponade (squeezes the heart), diabetes and obesity. Diseases such as hemochromatosis or amyloidosis that cause the heart to stiffen, thus decreasing the hearts ability to relax.

All of the above can cause the heart to become a weaker pump, thus resulting in a loss of cardiac output, and causing pulmonary edema.

Treatment for CHF?

According to the Mayo Clinic, "You can't reverse many conditions that lead to heart failure, but heart failure can often be treated with good results. Medications can improve the signs and symptoms of heart failure."

Acute heart failure must be treated in the emergency room or other hospital setting. Otherwise, heart failure can be controlled by medicine (to see a list of medicines used to treat CHF, click here).

Another way of treating CHF is by making certain lifestyle changes, such as quitting smoking, eating a healthy diet, limiting salt intake (to lower blood pressure), exercising to the best of your ability, taking your blood pressure medicines as prescribed by your physician, as well as taking all your meds as prescribed. You'll also need to manage stress, manage depression, manage anxiety, lose weight, control diabetes, and lose weight if you're too overweight.

Actually, by doing the things in the above paragraph you may be able to prevent CHF from occurring. They key here is you need to be aware early on in your life you are at risk, and take care of yourself.

Acute heart failure is asymptomatic, or acute or ongoing (see symptoms below), it's always a good idea to limit salt and water intake until the kidneys have had a chance to balance out electrolytes in your body, and your symptoms are controlled.

Since cardiac anomalies such as leaky valves and congenital heart anomalies such as tetrology of ferot (for more anomalies click here) can cause CHF, surgical procedures can be performed to correct such anomalies.

For acute (or ongoing symptoms) your respiratory therapist or nurse will put you on oxygen as necessary to make sure your heart and tissues are adequately oxygenated. Quite often, if your symptoms are severe, a mask (non-rebreather) is used to give you 100% oxygen until your symptoms resolve and your breathing is improved.

Sometimes a BiPAP machine is needed. This is where a mask is placed over your face to assist you with your breathing. This is used to help remove the fluid from your lungs and to make breathing easier (to learn more about BiPAP click here, here, here and here).

If your symptoms get really bad, and you start to tire out, a breathing tube may be inserted into your lungs and your breathing performed by a breathing machine (ventilator). Both the BiPAP and Ventilator are only temporary, and are removed as you improve.

(To learn about the medicine used to treat heart failure, click here.)

When can heart failure lead to death?

Heart failure, if untreated, can lead to death because other organs of the body will not be receiving enough oxygen. Usually one of the first organs to be effected are the kidneys, which will fail and lose their ability to excrete salts and water, and actually cause your body to retain more fluid. Actually, kidney failure alone can lead to pulmonary edema, or exacerbate it.

Likewise, fluid will back up in the liver, which in turn will fail in its job of removing toxins from the body. Lacking oxygen, the large and small intestines will lose their ability to absorb nutrients, and thus one organ after another will fail, ultimately leading to death.

What are symptoms of heart failure

Heart Failure is a chronic disease, and the ultimate goal of those with this disease is to prevent acute symptoms. However, from time to time, symptoms will occur regardless of treatment. The key is to know the symptoms and to get to the emergency room as fast as you can. Note that the earlier you get to the ER, the greater your chances of recovering.

I have seen from time to time a CHF patient waits too long, and the damage to the body is so bad there is nothing the attending ER doctor can do to save the patient. On the other end of the spectrum, I've seen patients come in early enough where the doctor can treat the symptoms and the patient actually went home the same day.

However, most patients will require at least a brief inpatient stay. That's what you should expect.

As noted by the Mayo Clinic, symptoms of CHF are:

Chronic heart failure symptoms:
  1. Shortness of breath, or dyspnea with exertion, or with minimal activity
  2. Shortness of breath when lying down (called orthopnea). You have to sit up to breath.
  3. Swelling (edema) in your legs or ankles
  4. Rapid or irregular heart beat
  5. Reduced ability to exercise
  6. Increased wheezing that is often audible
  7. Excessive secretions that are white or pink and frothy (call an ambulance if at this point)
  8. Swelling of abdomen (ascites)
  9. Sudden weight gain (from fluid retention)
  10. Lack of apetite
  11. Nausea
  12. Difficulty concentrating or decreased alertness
Acute Heart Failure Symptoms:

  1. Same as Chronic heart failure, but more severe
  2. Sudden fluid buildup
  3. Rapid or irregular heartbeat (palpitations)
  4. Sudden or severe shortness of breath
  5. Coughing up pink frothy secretions
  6. Chest pain, especially if heart failure caused by heart attack
When to see a doctor:

  1. Chest pain
  2. Fatigue and weakness
  3. Rapid or irregular heartbeat
  4. Shortness of breath (dyspnea) when you exert yourself or when you lie down
  5. Reduced ability to exercise
  6. Persistent cough or wheezing with white or pink blood-tinged phlegm
  7. Swelling in your abdomen, legs, ankles and feet
  8. Difficulty concentrating or decreased alertness
What can lead to worsening CHF?

According "Respiratory Disease: Principles of Patient Care," the following can lead to acute heart failure:

A. Patient induced:

  1. Failure to take medicine
  2. Excessive salt intake
  3. High alcohol ingestion
  4. Physical inactivity or over-activity
  5. Emotional stress
B. Infection: Viral or Bacterial (Sepsis)

C. Arrhythmias: Irregular heart beats (palpitations) such as preventricular contractions (PVC), heart block, bradycardia (heart not able to beat fast enough to pump blood), tachycardia (heart working too hard to pump blood will eventually fail)

D. Excessive fluid administration: This can sometimes result after blood transfusions

E. Pulmonary Embolism: A blood clot can form anywhere in the body and work it's way to the lungs, and thus block a portion of the lungs, causing the heart to work extra hard to pump blood to the lungs.

F. High Cardiac Output demand: Anything that causes your heart to beat too fast, such as when your body requires more oxygen than the heart can pump out:

  1. Fever
  2. Anemia
  3. Pregnancy
  4. Hypermetabolism
G. Heart Attack or ischemia: Lack of oxygen to the heart, or an inability of the heart to function.

H. Renal (Kidney) failure: As noted above, the kidneys are responsible for regulating fluid, and as fluid backs up, this can cause the heart to work too hard.

I. Respiratory Failure: As noted above.

J. Liver disease: As noted above.

K. Drug induced Failure: As noted above

L. Environmental Stress: Hyperthermia (Fever) or Hypothermia (excessive cold)So heart failure can be acute, although the workings that cause it have usually been going on for several years. If you can treat the ultimate causes, you can prevent or delay the onset of this disease.

Likewise, if you notice the signs and symptoms of CHF, make sure you notify your doctor immediately. If you notice the signs of acute CHF, get yourself to the emergency room right away. The quicker you seek help, the greater your chances of surviving the episode.

What is the life expectancy of CHF patients?

Actually, about 50% of patients diagnosed with CHF die within 2 years of diagnosis (5), and this is ultimately due to the hearts poor ability to oxygenate tissues of the body, gradually leading to multi organ failure.

Some people, with good care and good compliance with recommended therapies, lifestyle changes, medicines, vigilance of symptoms, and swift action during acute episodes can live much longer. I wrote about this in more detail in this post.

Information for this post came from the following sources:
5. "
Respiratory Disease: Principles of Patient Care," ed. Robert L. Wildins, James R. Dexter, (F.A. Davis Company), Philadelphia.

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